Function CheckVarStd

cpp/src/arrow/compute/kernels/aggregate_test.cc:3293–3302

//

void CheckVarStd(const Datum& array, const VarianceOptions& options,
                 double expected_var) {
  ASSERT_OK_AND_ASSIGN(Datum out_var, Variance(array, options));
  ASSERT_OK_AND_ASSIGN(Datum out_std, Stddev(array, options));
  auto var = checked_cast<const DoubleScalar*>(out_var.scalar().get());
  auto std = checked_cast<const DoubleScalar*>(out_std.scalar().get());
  ASSERT_TRUE(var->is_valid && std->is_valid);
  AssertWithinUlp(std->value * std->value, var->value, /*n_ulps=*/2);
  AssertWithinUlp(var->value, expected_var, /*n_ulps=*/5);
}

template <typename ArrowType>
class TestPrimitiveVarStdKernel : public ::testing::Test {